iMatch: A retention index tool for analysis of gas chromatography-mass spectrometry data
iMatch: A retention index tool for analysis of gas chromatography-mass spectrometry data
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DOI：
10.1016/j.chroma.2011.07.039
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发表时间：
2011-09-16
影响因子：
4.1
通讯作者：
Zhang, Xiang
中科院分区：
文献类型：
--
作者：
Zhang, Jun;Fang, Aiqin;Zhang, Xiang
利用美国国家标准与技术研究所（NIST）2008年保留指数数据库信息，通过构建保留指数绝对偏差与平均值的经验分布函数（DF）进行分子保留匹配。首先评估了不同实验参数对分子保留指数的影响。色谱柱类别、色谱柱类型和数据类型对毛细管色谱柱上获得的保留指数值有显著影响。然而，在斜坡条件下的正构烷烃保留指数（I（norm））与线性保留指数（I（T））相似，而在等温条件下的I（norm）与Kovats保留指数（I）相似。对于复杂条件下的I（范数），这些数据应作为一个附加组处理，因为极柱的平均I（范数）值与I（T）显著不同。基于该分析，从分组保留指数数据生成九个DF。DF信息进一步实施到名为iMatch的软件程序中。使用标准品和加标标准品的大鼠血浆代谢物提取物混合物的实验数据评价iMatch的性能。约19%的由ChromaTOF鉴定的分子被iMatch从电子电离（EI）质谱匹配的鉴定列表中过滤掉，而所有加标的标准品被保留。分析结果表明，使用保留指数值，通过构造一组DF，可以通过减少假阳性的显着部分来改善基于光谱匹配的识别。(C)2011 Elsevier B.V.保留所有权利。
A method was developed to employ National Institute of Standards and Technology (NIST) 2008 retention index database information for molecular retention matching via constructing a set of empirical distribution functions (DFs) of the absolute retention index deviation to its mean value. The effects of different experimental parameters on the molecules' retention indices were first assessed. The column class, the column type, and the data type have significant effects on the retention index values acquired on capillary columns. However, the normal alkane retention index (I(norm)) with the ramp condition is similar to the linear retention index (I(T)), while the I(norm) with the isothermal condition is similar to the Kovats retention index (I). As for the I(norm) with the complex condition, these data should be treated as an additional group, because the mean I(norm) value of the polar column is significantly different from the I(T). Based on this analysis, nine DFs were generated from the grouped retention index data. The DF information was further implemented into a software program called iMatch. The performance of iMatch was evaluated using experimental data of a mixture of standards and metabolite extract of rat plasma with spiked-in standards. About 19% of the molecules identified by ChromaTOF were filtered out by iMatch from the identification list of electron ionization (EI) mass spectral matching, while all of the spiked-in standards were preserved. The analysis results demonstrate that using the retention index values, via constructing a set of DFs, can improve the spectral matching-based identifications by reducing a significant portion of false-positives. (C) 2011 Elsevier B.V. All rights reserved.